Bleaching and washing composition



Patented Apr. 7, 1925.

BLEACHING AND WASHING COMPOSITION.

No Drawing.

chlorite, a considerable quantity of the lime,

however, remaining in the unconverted state. This material is used for a great variety of purposes, such as for whitening goods and for cleaning purposes and owes 9 its effectiveness to the oxidizing action of the oxygen evolved by a combination of a portion of the chlorine of the bleaching powder with the hydrogen of water. This material has been put upon the market in the form of a dry powder and when freshly made is very efiicientfor the purposes for which it is used. As ordinarily made, however, it rather rapidly loses its effectiveness, becoming largely converted into calcium chloride with the evolution of oxygen. In order to so far as possible preserve the materi'al in its full strength it is commonly enclosed in moisture excluding packages, but even with. this precaution it becomes weak and ineffective after the lapse'of a comparatively short period. 1

It is the purpose of my invention to enhancethe bleaching effect of bleaching powder and'also to so preserve itthat it may be kept a considerable time without appreciable loss of strength. It is a further purpose of the invention to avoid any deleterious effectof the released chlorine upon the material treated with the bleaching powder. I have discovered that if the bleaching powder is mixed with sodium bicarbonate a much more intense bleaching effect is obtained and that if the bicarbonate is mixed dry with the freshly formed Application filed December 17, 1921. Serial No. 523,170.

bleaching powder the disagreeable odor of the latter is largely removed, the compound will keep well without unduly losing strength and when'the mixture is dissolved in water a reaction takes places in which the calcium of the bleaching powder is precipitated in the form of carbonate. If the bicarbonate is added to a solution of the bleaching powder a double decomposition takes place, the reaction proceeding so energetically as to cause considerable effervescence, due to the evolution of chlorine and oxygen and thus a considerable portion of these gases is lost without doing the-intended work. When, however, the bleaching powder and bicarbonate are mixed dry and subsequently dissolved in water the reaction takes place very much more slowly with the result that the chlorine and oxygen enter fully into the bleaching action and consequently the efi'ect is greatly enhanced. Preferably the bicarbonate is added in smaller quantity than is required to combine with all of the calcium of the hypochlorite.

In preparing the commercial article I add about three parts of fresh bleaching powder, which may be prepared in the usual manner, to about one part of sodium bicarbonate, thoroughly mixing these materials and reducing any lumps therein to powder. The mixture is preferably shipped and stored in closed receptacles such as those commonly employed for bleaching powder, though as my composition retains its strength better than ordinary bleaching powder, thls 1s not essential.

Where I have used the term bleaching powder or calcium hypochlorite, I wish to be understood as referring to a compound containing calcium'hypochlorite (CaCl O) such as is commonly found on the market un- 1 der the name of bleaching powder. By the term sodium bicarbonateI mean to referto sodium acid carbonate (NaHCO or sodium hydrogen carbonate, commonly known as baking soda.

Where the composition is dissolved-in water in considerable concentration as where a powerful bleaching effect is desired, the calcium carbonate which forms may be allowed to settle, and'the supernatant liquor decanted off and used for the purpose. When the material is used in greaterdilution no settling is required. In case the compound is used for scrubbing or the like the insoluble carbonate of lime formed is readily washed away.

- ture of dry and calcium hypochlorite.

2. As an article of manufacture, a mixhypochlonte.

BERTRAND s. SUMMERS.

an article of manufacture, a mixsodium bicarbonate and calcium 15 

